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1.
The next generation of interactive multimedia documents can contain both static media, e.g., text, graph, image, and continuous
media, e.g., audio and video, and can provide user interactions in distributed environments. However, the temporal information
of multimedia documents cannot be described using traditional document structures, e.g., Open Document Architecture (ODA)
and Standard Generalized Mark-up Language (SGML); the continuous transmission of media units also raises some new synchronization
problems, which have not been met before, for processing user interactions. Thus, developing a distributed interactive multimedia
document system should resolve the issues of document model, presentation control architecture, and control scheme. In this
paper, we (i) propose a new multimedia document model that contains the logical structure, the layout structure, and the temporal
structure to formally describe multimedia documents, and (ii) point out main interaction-based synchronization problems, and
propose a control architecture and a token-based control scheme to solve these interaction-based synchronization problems.
Based on the proposed document model, control architecture, and control scheme, a distributed interactive multimedia document
development mechanism, which is called MING-I, is developed on SUN workstations. 相似文献
2.
The Personal Presence System (PPS) is an experimental research prototype platform to support advanced broadband applications,
including multimedia conferencing and distance learning. It supports the user's presentation control of advanced network elements
(multimedia bridges). The multimedia bridge provides for a single contact point per user, who receives only one combined video
stream, which minimizes access bandwidth. This architecture solves the -squared transmission problem of multipoint video conferencing and makes customer terminal equipment simpler and cheaper than
high-end desktop workstations. The PPS provides each user with flexible presentation control of a feature-rich video bridge.
The PPS also supports advanced features such as object extraction and multimedia object associations. 相似文献
3.
One of the challenges in the design of a distributed multimedia system
is devising suitable specification models for various schemas in
different levels of the system.
Another important research issue is
the integration and synchronization of heterogeneous multimedia
objects. In this paper, we present our models for multimedia schemas
and transformation algorithms. They transform high-level
multimedia objects into schemas that can be used to
support the presentation and communication of the multimedia objects.
A key module in the system is the Object Exchange Manager (OEM). In this paper,
we present the design and implementation of the OEM module,
and discuss in detail the interaction
between the OEM and other modules in a
distributed multimedia system. 相似文献
4.
In this paper, we present a novel approach for multimedia data indexing and retrieval that is machine independent and highly
flexible for sharing multimedia data across applications. Traditional multimedia data indexing and retrieval problems have
been attacked using the central data server as the main focus, and most of the indexing and query-processing for retrieval
are highly application dependent. This precludes the use of created indices and query processing mechanisms for multimedia
data which, in general, have a wide variety of uses across applications. The approach proposed in this paper addresses three
issues: 1. multimedia data indexing; 2. inference or query processing; and 3. combining indices and inference or query mechanism
with the data to facilitate machine independence in retrieval and query processing. We emphasize the third issue, as typically
multimedia data are huge in size and requires intra-data indexing. We describe how the proposed approach addresses various
problems faced by the application developers in indexing and retrieval of multimedia data. Finally, we present two applications
developed based on the proposed approach: video indexing; and video content authorization for presentation. 相似文献
5.
Igor D.D. Curcio Antonio Puliafito Salvatore Riccobene Lorenzo Vita 《Multimedia Systems》1998,6(6):367-381
The relative simplicity of access to digital communications nowadays and the simultaneous increase in the available bandwidth
are leading to the definition of new telematic services, mainly oriented towards multimedia applications and interactivity
with the user. In the near future, a decisive role will be played in this scenario by the providers of interactive multimedia
services of the on-demand type, which will guarantee the end user a high degree of flexibility, speed and efficiency. In this
paper, some of the technical aspects regarding these service providers are dealt with, paying particular attention to the
problems of storing information and managing service requests. More specifically, the paper presents and evaluates a new storage
technique based on the use of disk array technology, which can manage both typical multimedia connections and traditional
requests. The proposed architecture is based on the joint use of the partial dynamic declustering and the information dispersal
algorithm, which are employed for the allocation and retrieval of the data stored on the disk array. We also define efficient
strategies for request management in such a way as to meet the time constraints imposed by multimedia sessions and guarantee
good response times for the rest of the traffic. The system proposed is then analyzed using a simulation approach. 相似文献
6.
John Kominek 《Multimedia Systems》1997,5(4):255-270
Fractal image compression is a promising new technology but is not without problems. Most critically, fast encoding is required
for it to find wide use in multimedia applications. This is now within reach: recent methods are five orders of magnitude
faster than early attempts. Beginning with the basic ideas and problems, this paper explains how to accelerate fractal image
compression. 相似文献
7.
Dynamic batching policies for an on-demand video server 总被引:18,自引:0,他引:18
In a video-on-demand environment, continuous delivery of video streams to the clients is guaranteed by sufficient reserved
network and server resources. This leads to a hard limit on the number of streams that a video server can deliver. Multiple
client requests for the same video can be served with a single disk I/O stream by sending (multicasting) the same data blocks
to multiple clients (with the multicast facility, if present in the system). This is achieved by batching (grouping) requests
for the same video that arrive within a short time. We explore the role of customer-waiting time and reneging behavior in
selecting the video to be multicast. We show that a first come, first served (FCFS) policy that schedules the video with
the longest outstanding request can perform better than the maximum queue length (MQL) policy that chooses the video with
the maximum number of outstanding requests. Additionally, multicasting is better exploited by scheduling playback of the
most popular videos at predetermined, regular intervals (hence, termed FCFS-). If user reneging can be reduced by guaranteeing that a maximum waiting time will not be exceeded, then performance of FCFS- is further improved by selecting the regular playback intervals as this maximum waiting time. For an empirical workload,
we demonstrate a substantial reduction (of the order of 60%) in the required server capacity by batching. 相似文献
8.
9.
Multimedia databases 总被引:2,自引:0,他引:2
A.Desai Narasimhalu 《Multimedia Systems》1996,4(5):226-249
The rapidly growing interest in building multimedia tools and applications has created a need for the development of multimedia
database management systems (MMDBMSs) as a tool for efficient organization, storage and retrieval of multimedia objects. We
begin with a word about traditional database management systems (DBMSs). Then we present an overview of the MMDBMS research
issues, challenges, methods, models, and architectures. We review the state of the art and research contributions from related
disciplines. Finally, we consider possibilities and probabilities for MMDBMS research in the future. 相似文献
10.
Nevzat Hurkan Balkir Gultekin Ozsoyoglu 《The VLDB Journal The International Journal on Very Large Data Bases》1998,7(4):294-307
Most multimedia servers reported in the literature are designed to serve multiple and independent video/audio streams. We
think that, in future, multimedia servers will also serve complete presentations. Multimedia presentations provide unique
opportunities to develop algorithms for buffer management and admission control, as execution-time consumption requirements
of presentations are known a priori. In this paper, we examine presentations in three different domains (heavyweight, middleweight,
and lightweight) and provide buffer management and admission control algorithms for the three domains. We propose two improvements
(flattening and dynamic-adjustments) on the schedules created for the heavyweight presentations. Results from a simulation
environment are presented.
Received June 9, 1998 / Accepted October 13, 1998 相似文献
11.
Easy-to-use audio/video authoring tools play a crucial role in moving multimedia software from research curiosity to mainstream
applications. However, research in multimedia authoring systems has rarely been documented in the literature. This paper describes
the design and implementation of an interactive video authoring system called Zodiac, which employs an innovative edit history abstraction to support several unique editing features not found in existing commercial
and research video editing systems. Zodiac provides users a conceptually clean and semantically powerful branching history model of edit operations to organize the authoring process, and to navigate among versions of authored documents. In addition,
by analyzing the edit history, Zodiac is able to reliably detect a composed video stream's shot and scene boundaries, which facilitates interactive video browsing.
Zodiac also features a video object annotation capability that allows users to associate annotations to moving objects in a video sequence. The annotations themselves could
be text, image, audio, or video. Zodiac is built on top of MMFS, a file system specifically designed for interactive multimedia development environments, and implements an internal buffer
manager that supports transparent lossless compression/decompression. Shot/scene detection, video object annotation, and buffer
management all exploit the edit history information for performance optimization. 相似文献
12.
Without user interactions, multimedia presentations are just fancy slide shows with sound and video supports. User interactions
by themselves do not change the temporal relationships among multimedia objects, such as texts, graphics, images, audio, and
video, but affect the playback schedules. In this paper, we propose a synchronization mechanism to guarantee the quality of
multimedia presentation with user interactions. In our protocol, each presentation site requests media transmission from the
required media servers at certain time intervals prior to the playback deadlines, where these time intervals are the response
times to cover possible experienced end-to-end delays and packet losses, and waits for an initial setup time to ensure intermedia
synchronization before starting the presentation. Users may interact with the presentation. This synchronization mechanism
solves the problems incurred by user interactions by determining the new presentation scenario produced by the interactive
operation, calculating the corresponding setup time, and then rendering the new playback and retrieval schedules. 相似文献
13.
Luiz Fernando G. Soares Rogério F. Rodrigues Débora C. Muchaluat Saade 《Multimedia Systems》2000,8(2):118-134
This paper discusses multimedia and hypermedia modeling, authoring and formatting tools, presenting the proposals of the
HyperProp system and comparing them to related work. It also highlights several research challenges that still need to be
addressed. Moreover, it stresses the importance of document logical structuring and considers the use of compositions in order
to represent context relations, synchronization relations, derivation relations and task relations in hypermedia systems.
It discusses temporal and spatial synchronization among multimedia objects and briefly presents the HyperProp graphical authoring
and formatting tools. Integration between the proposed system and the WWW is also addressed. 相似文献
14.
K. Selçuk Candan Eric Lemar V.S. Subrahmanian 《The VLDB Journal The International Journal on Very Large Data Bases》2000,9(2):131-153
Abstract. Though there has been extensive work on multimedia databases in the last few years, there is no prevailing notion of a multimedia
view, nor there are techniques to create, manage, and maintain such views. Visualizing the results of a dynamic multimedia
query or materializing a dynamic multimedia view corresponds to assembling and delivering an interactive multimedia presentation
in accordance with the visualization specifications. In this paper, we suggest that a non-interactive multimedia presentation
is a set of virtual objects with associated spatial and temporal presentation constraints. A virtual object is either an object, or the result of a query.
As queries may have different answers at different points in time, scheduling the presentation of such objects is nontrivial.
We then develop a probabilistic model of interactive multimedia presentations, extending the non-interactive model described
earlier. We also develop a probabilistic model of interactive visualization where the probabilities reflect the user profiles,
or the likelihood of certain user interactions. Based on this probabilistic model, we develop three utility-theoretic based
types of prefetching algorithms that anticipate how users will interact with the presentation. These prefetching algorithms
allow efficient visualization of the query results in accordance with the underlying specification. We have built a prototype
system that incorporates these algorithms. We report on the results of experiments conducted on top of this implementation.
Received June 10, 1998 / Accepted November 10, 1999 相似文献
15.
Due to their large bandwidth demand and synchronization requirements, multimedia applications, in general, consume buffers
of huge size, which prevents potential customers from using multimedia services. We recognize the problem and propose a hierarchical
architecture to reduce the buffer size. The architecture can be applied to both 1- and - applications. We establish the architecture by first determining neighbor sets and then applying a grouping algorithm and
a renegotiation process. This architecture can also meet the synchronization requirements of multimedia applications. We evaluate
the performance of the architecture through simulations and compare it with that of a direct connection architecture. The result shows that the hierarchical architecture reduces the buffer size significantly without
serious penalty to the total bandwidth and without introducing extra hot spots. 相似文献
16.
In this paper, we propose a new communication abstraction known as the group channel which facilitates and supports the implementation
of multiparty interactive multimedia (MIM) applications such as video conferencing. The group channel is a high-level abstraction for group communication. The credit scheme and the dynamic bandwidth calibration scheme are provided as an integral part of the group channel service for allocating
network bandwidth dynamically as participants join and leave the group channel. The multimedia transport protocol (MTP) is
proposed as a realization of the group channel service in the ATM network. Its prototype implementation and a simple multiparty
video-conferencing application built on top of the MTP prototype are described in this paper. Our results show that the group
channel is capable of guaranteeing the performance of MIM applications irrespective of the group size and differences in workstation
speeds. 相似文献
17.
Eve M. Schooler 《Multimedia Systems》1996,4(5):210-225
As integrated services have become available to the desktop, users have embraced new modes of interaction, such as multimedia
conferencing and collaborative computing. In this paper, we provide a survey of past and present research that has influenced
this application area, and describe research directions for the future. 相似文献
18.
Domenico Ferrari 《Multimedia Systems》1998,6(3):179-185
The research done by the Tenet Group in multimedia networking has reached a point where it may be useful to reflect on the
significance of its results for the current debate on how integrated-services internetworks should be designed. Such reflections
constitute the main subject of this paper. The principles of the work and the conclusions reached so far by the Tenet researchers
are discussed in the light of the conflict between the two major technologies being proposed to build future information infrastructures:
namely, the Internet and the ATM technologies. The Tenet approach suggests one feasible way for resolving the conflict to
the advantage of all the users of those infrastructures. This paper discusses various fundamental aspects of integrated-services
network design: the choice of the service model, the type of charging policy to be adopted, and the selection of a suitable
architecture. 相似文献
19.
As multimedia applications spread widely, it is crucial for programming and design support systems to handle “time” in multimedia
documents effectively and flexibly. This paper presents a set of interactive system support tools for designing and maintaining
the temporal behavior of multimedia documents. The tool set provides mechanisms for anomaly detection, temporal query processing,
and interactive scheduling. It is based on a fast incremental constraint solver we have developed, which can be adapted by
any constraint-based system. The incremental constraint solver provides immediate feedback to the user, supporting a highly
interactive design process. Combined with existing optimal layout generation mechanisms proposed in the literature, our tools
effectively utilize the flexibility provided by constraint-based systems. 相似文献
20.
Lawrence D. Bergman Jerre Shoudt Vittorio Castelli Chung-Sheng Li Loey Knapp 《International Journal on Digital Libraries》1999,2(2-3):178-189
In this paper, we describe a new interface for querying multimedia digital libraries and an interface building framework.
The interface employs a drag-and-drop style of interaction and combines a structured natural-language style query specification
with reusable multimedia objects. We call this interface DanDMM, short for “drag-and-drop multimedia”. DanDMM interfaces capture
the syntax of the underlying query language, and dynamically reconfigure to reflect the contents of the data repository.
A distinguishing feature of DanDMM is its ability to synthesize integrated interfaces that incorporate both example-based
specification using multimedia objects, and traditional techniques including keyword, attribute, and free text-based search.
We describe the DanDMM-builder, a framework for synthesizing DanDMM interfaces, and give several examples of interfaces that
have been constructed using DanDMM-builder, including a remote-sensing library application and a video digital library.
Received: 15 December 1997 / Revised: June 1999 相似文献